Colonoscopy coding can be confusing because there are many codes from which to choose. This guide explains the difference between screening and diagnostic colonoscopies. It also discusses when to use HCPCS codes and CPT® codes, and specific colonoscopy modifiers.

Reading the procedure report before assigning any codes is very important. Screening procedures can easily turn into diagnostic (e.g., biopsy for further review) or therapeutic (treating a found issue) procedures and these cases may require modifiers or specific codes based on insurance. Screening colonoscopy services are paid without a patient due balance, while diagnostic colonoscopies have patient due balances. Using correct modifiers can increase the likelihood that a procedure that is scheduled as a screening but converts to a diagnostic procedure won’t have a patient balance.

Understanding these distinctions is crucial for accurate billing and compliance with payer requirements. By following the guidance in this document, you can help ensure correct reimbursement and minimize claim denials.

Table of Contents

• The Purpose of This Guide
• Coding for Screening Colonoscopy
• Procedure Coding for Colonoscopies
• Diagnosis Coding for Screening Colonoscopy